Fuse



' 1,555,753 Dec. 15 1925 E. L. OGLE FUSE Filed Sept. 1, 1921 PatentedDec. 15, 1925.

UNITED STATES PATENT OFFICE.

ELMER L. OGLE, OF CHICAGO, ILLINOIS, ASSIGNOR TO FEDERAL ELECTRICCOMPANY,

OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

FUSE.

Application filed September 1, 1921i Serial No. 497,585.

To all whom it may concern:

Be it known that I, ELMER L. OGLE, a citi- Zen of the United States, anda resident of Chicago, county of Cook, and State of lllinois, haveinvented certain new and useful Improvements in Fuses; and I do herebydeclare that the following is a full, clear, and exact descriptionthereof, reference being had to the accompanying drawings, and

to the letters of reference marked thereon,

which form a part of this specification.

This invention relates to overload circuit breakers, commonly known asfuses, and consists of the matters hereinafter described and moreparticularly pointed out in the appended claim.

The invention relates to a novel and improved fuse for use in multiphasecircuits, which is adapted, upon an overload and resulting opening ofthe circuit of one phase, to open the circuit of the other phase orphases.

The improved fuse is generally of the construction described andillustrated in an application for patent (filed August 29,

1921, Ser. No. 496,207), and contains a renewable cartridge in which isa heating coil designed to be connected with the terminals of anothercircuit.

The object of the invention is to provide a simple and efficient devicefor connecting the heating coil of the fuse with the second circuit andat the same time produce a de vice of the kind which is cheap and eco- 3nomical to manufacture and is capable" of ready and easy assembly.

The advantages of the invention will ap pear as I proceed with myspecification.

In the drawings:

Figure 1 is a diagrammatic view, showing my improved fuse as applied andconnected in a three-phase system.

Figure 2 represents an enlarged side elevation of the fuse, with part ofthe fuse body broken away near one end to show the cartridge.

Figure 3 is a fragmental longitudinal section through the fuse, greatlyexaggerated.

Figure 4 is a section through Figure 3 in a plane indicated by the lineH of Fig. 3.

Figure 5 is a perspective View of the two parts of theconnecting device,as used when for front connected installation.

Figure 6 is a sectional view showing the connecting device as when usedwith a back connected installation.

Referring now to that embodiment of the invention illustrated in thedrawings: 10 indicates the improved fuse, which is of the knife bladetype. Three such fuses 10, 10 and 10 are shown in the diagrammatic viewof Figure 1, each connection in one of the mains 11, 11, 11 of a threephase system, which are connected to a motor or other translating deviceindicated at 12. Each fuse contains a heating coil connected in multiple(in shunt as illustrated) by conductors 13, 13-18, 13 -13 13 to anothercircuit: the conductors 13, connecting the heating coil of the fuseblock 10 to the main 11; the conductors 13, connecting the heating coilof the fuse block 10 to the main 11 and the conductors 10 connecting theheating coil of the fuse block 13 to the main 11. This is familiarpractice with fuse blocks of the kind.

The fuse itself comprises a fibre body 14 with metallic heads 15, 16,each carrying a blade contact 15 16, and an enclosed cartridge 17containing fusible bars, the tell tale tags of which are indicated at18, and a heating coil with terminals (not shown) connected to twospring contacts on the outside of the cartridge body, one of whichcontacts is shown exposed at 19. The construction of the fuse in theseparticulars is fully disclosed in the application above referred to andas the details of said construction form no part of the presentinvention ithey need not be more particularly described iere.

Terminals 20, 20 are provided on the outside of the body 14; of the fusefor connecting the contacts 19 of the heating coil of the cartridge withthe conductors which connect said heating coil with another circuit.Where said terminals are for front connected work, as shown in Figures 1to 5, the terminal consists of a stud having a reduced, threaded end 21of a length slightly greater than the thickness of the wall of the fusebody, with a radial shoulder 22 at the top of the thread. The stud has atransverse bore 23, near its top, for the insertion of a conductor wireand is tapped at the top to intersect said bore soas to receive a screw24c adapted to engage and hold the wire conductor in place.

Y tact and 27 a threaded. stud thereon. 28'

In the fibre body 14 of the fuse is tapped a hole, and an internallythreaded thimble 25 is screwed into said hole, with its inner endextending beyond the inner surface of the tubular body of the fuse. Theouter end 26 of the thimble, which is reduced in thickness, is turneddown and riveted against the outer surface of the fuse body. ducedthreaded end 21 of the terminal 20 is screwed into the thimble until itsshoulder 22 engages against theriveted, end of the thimble, when its endwill be flush with the inner end of the thimble, thus providing acontact surface for engagement with the spring contact 19 of the heatingcoil of the cartridge. I V

Suchterminal device connection is also applicable for use with backconnected work where a blade contact is used, such as described inPatent No. 1,485,703 granted to me'on March 5L, 1924-. This isiillustrated in Fig. (3, where 27 indicates the blade 'con indicates theinternally threaded thimble, threaded into the body 14 of the fuse asbefore. I I

A terminal connection of the kind described is readily and cheaplymanufactured and is manifestly adaptable for either back connected orfront connected installation.

The rethe cylindrical fuse body adapted to connect I claim as myinvention:

In an electric fuse for use in multiphase circuits, in combination witha cylindrical fuse body and a removable cartridge containing a fusibleelement and a heating coil associated therewith, said cartridge havingauxiliary contacts on the outside of its body connected to said heatingcoil, terminals on sa'idauxiliary contacts with conductors outside ofsaid fuse, each terminal consisting of a member adapted for connectionwith an outside conductor, said member having a reduced, threaded end,the fuse body being provided with a threaded hole, a tubular internallyand externally threaded thimble engaged in the hole in said body andprojecting'beyond the body 'walljon one side and having its outer endturned down against the cylindrical outside surface of said fuse body'to lock the thimble against turning With respect to said fuse body, andthe reduced threaded end of said terminal'inemher being screwed intosaid thimble with its end flush with the inner end of said thimble inposition to engage said auxiliary contact.

In testimony that I claim the foregoing as my invention, I aflix mysignature, this 15th day of August, A. D. 1921.

ELMER L. OGLE.

